Container bottom closing



3 Sheets-Sheet l INVENTOR ff/6 ,4. 5,84 U/V March 3, 1970 E. A. BRAUN CONTAINER BOTTOM CLOSING Filed March 11, 1968 b\ EN @l w\\\ M6.. f/W

ATTORNEY March 3, 1970 3 Sheets-Shea*l 2 Filed March 11, 1968 ATTORN EY E. A. BRAUN CONTAINER BOTTOM CLOSING March 3, 1970 I5 Sheets-Sheet 3 Filed March 11, 1968 FIG.6

A TTORNE Y United States Patent 3,498,524 CONTAINER BOTTOM CLOSING Eric A. Braun, Framington, Mich., assignor to Ex-Cell-O Corporation, Detroit, Mich. Filed Mar. 11, 1968, Ser. No. 712,033 Int. Cl. B65d 5/08 U.S. Cl. 229-38 7 Claims ABSTRACT OF THE DISCLOSURE The bottom closure is a thermal plastic coated paperboard container having tuck-in flaps provided with extended cam edges to guide the bottom closure panels into closing position.

The present invention relates generally to a container closure structure and in its specilic embodiment to a bottom closure for a thermal plastic coated paperboard container.

During recent developments in the packaging industry many of the disposable containers commonly available have been adapted to package many new and different products. At the same time machine speeds have increased providing for variousactions to take place on a container structure in a much more rapid fashion. Due to the inherent characteristics of the container structures adapted for various products the containers function in somewhat different manner thus requiring modifications to be made to insure proper forming, filling and sealing.

Because of the new applications and new research and technical advancements when applying present containers to new products and increased fabricating machine speeds, it has been discovered that some containers; for example, thermal plastic coated paperboard containers may have their paperboard content reduced in wall thickness or in paperboard density and still perform properly when fabricated. This has required that some modifications he taken to insure proper action of the elements of the container during fabrication to eliminate and/ or hold to a minimum containers damaged during the fabricating stages.

When combining less rigid containers in packaging machinery operated at higher speeds the necessity of modifying the container becomes even more critical.

Illustrations of thermal plastic paperboard containers which are in common use would be shown in U.S. Patent 3,120,335 issued Feb. 4, 1964, which covers the bottom closure of such a container, and U.S. Patent 3,270,940 issued Sept. 6, 1966, which covers the top opening portion of such a container.

It is an objective of the present invention to provide a new and improved bottom tuck-in llap tip to provide failsafe tucking of the bottom closure panels.

Another object of the present invention is to provide a bottom tuck-in flap for a thermal plastic coated paperboard container'where at least one cam edge is provided to assist the tuck-in flap to move into closed position.

Still a further object of the present invention is to provide a tuck-in ilap bottom closure panel having a straight edge member which is a shorter length than the straight edge portion of the tuck-over flap.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the means and features hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain illustrative embodiments of the invention, such disclosed embodiments illustrating, however, but several of the various ways in which the principles of the invention may be used. In the annexed drawings;

3,498,524 Patented Mar. 3, 1970 FIGURE 1 is a laid out plan view of the inside surface of a container blank, with the inside panels broken away showing a top closure and a bottom closure illustrating the principles of the invention.

FIGURE 2 is a laid out plan view of the inside Surface of the bottom closure of a container blank showing an alternate bottom illustrating the inventive features of the present invention.

FIGURE 3 is a laid out plan view of the inside surface of the bottom closure of a container blank showing an alternate bottom illustrating the inventive features of the present invention.

FIGURE 4 is a perspective view illustrating the alternate embodiment of the bottom tuck-in panel and the bottom tuck-over panel as the bottom closure is being closed illustrating the principles of the invention as shown in FIGURE 1.

FIGURE 5 is a perspective view illustrating the alternate embodiment of the bottom tuck-in panel and the bottom tuck-over panel as the bottom closure is being closed illustrating the principles of the invention as shown in FIGURE 3.

FIGURE 6 is a partial end view of the bottom edge member illustrating the bottom tuck-in panel as it enters the pocket formed by the bottom tuck-over panel illustrating the principles of the present invention as shown in FIGURE 4.

FIGURE 7 is a perspective view of a constructed container illustrating the completed container showing the bottom closure group illustrating the principles of the container shown in FIGURES 1, 4 and 6.

Referring to FIGURE l, the inside surface of the container blank is illustrated and generally referred to as number 10. The container blank 10 is separated into three general groups by staggered score lines 11 and 12. The group above staggered score line 11 is referred to as top closure group 14. The group bottom staggered score lines 11 and 12 are referred to as body group 15. The

group below staggered score line 12 is referred to as bottom closure group 16. The container blank 10 is deiined on its sides by side edges 18 and 19. Container blank 10 is separated vertically by a series of score lines 21 through 24. The score lines 21 through 24 divide the group body 15 into side wall panels 26, 27, 28 and 29 and side seam ap 30.

Top closure group 14 is mounted on the upper end of body group 15. Triangular end panels 32 and 34 are mounted to upper ends of side wall panels 26 and 28, respectively. Triangular end panel 32 has a pair of adjacent fold-back panels 36 and 37 mounted on its upper sides and triangular end panel 34 has a pair of foldback end panels 38 and 39 mounted on its upper sides. A pair of inner rib panels 42 and 43 are mounted adjacent fold-back panels 36 and 37, respectively. A pair of inner rib panels 44 and 45 are mounted adjacent fold-back panels 38 and 39, respectively.

A pair of roof panels 47 and 49 are mounted to the body group 15 at the upper end of side wall panels 27 and 29, respectively. A pair of outer sealing rib panels 51 and 53 are mounted at the upper end of the roof panels 47 and 49, respectively. A top edge member 54 defines the upper free end of top closure group 14. A complete description of the top closure group 14 is not necessary to understand the principles of the present invention. However, reference is made to U.S. Patent 3,270,940 which issued Sept. 6, 1966 for a complete description of a top closure group similar to top closure group 14.

The bottom closure group 16 is mounted on the lower end of body group 15. Tuck-in flap 56 and tuck-out ap 58 are mounted at the lower ends of side wall panels 26 and 28, respectively, along staggered score line 12.

First minor flap 61 and second minor flap 63 are mounted at the bottom of side wall panels 27 and 29, respectively, along staggered score line 12. A pair of fold-back panels 64 and 65 connect tirst minor flap 61 to tuck-in flap 56 and tuck-out iiap 58, respectively. Second minor flap 63 is connected to tuck-out flap 58 and side seam flap 30 by fold-back panels 68 and 69, respectively.

A bottom edge member 70 defines the free end of bottom closure group 16. The bottom edge member 70 is substantially defined by three sections at the bottom edge of tuck-in ilap 56. These three sections or portions are dened by a cam edge 71, a straight edge 72 and a cam edge 73. The bottom edge member 70 is defined as edge portion 74 along the free edge of fold-back panels 64 and 65. Tuck-out panel 58 has its bottom edge member 70 defined by a free edge portion which is substantially au extension of score line 22, straight edge 75 and a diagonal edge 76. The free edge portion of fold-back panels 68 and 69 is dened by edge portion 77. The side seam flap 30 has its portion of bottom edge member 70 defined by diagonal edge 78.

` When the container blank is being prepared for assembly as a container it will be side seamed by having the roof panel 49, side Wall panel 29 and second minor ap 63 and its associated fold-back panels 68 and 69 along with side seam ap 30 folded about score line 23 moving their inside surfaces into contact with the inside surfaces of triangular end panel 34, side Wall panel 28 and tuck-out flap 58 and the side seam flap 30s inside surface extending past score line 22.

The triangular end panel 32, side wall panel 26 and the tuck-in flap 56 Will be rotated about score line 21 so their inside surfaces Will move toward the inside surface of roof panel 47, side Wall panel 27 and rst minor flap 61 and fold-back panels 64 and 65. The side edge 18 will then be substantially aligned with score line 24 and its associated edge portion will be aligned With and in Contact with the outside surface of side seam flap 30. The outside surface of side seam ap 30 is secured to the inside surface of the various panel and ap members being positioned along the side edge 18. This can be accomplished in many Ways. One of the preferred methods is heat sealing which Will establish a surface bond between the above stated members. The container blank 10 can then be opened into tubular form as illustrated in FIGURES 4, 5 and 7 as tubular container member 80.

In normal production operations the bottom closure group 16 will be closed and sealed, the contents will be passed into the tubular container member 80 and then the top closure group 14 Will be closed, as illustrated in FIGURE 7; for example, Where a completed container in its inverted form is shown.

The forming of the side seam blank and the closing of the top closure group is covered in detail in the above mentioned U.S. Patent 3,270,940. The diagonal edge 78 and diagonal edge 76 are provided so that when the container is constructed there Will not be an extra layer of paper as the tuck-out ap 58 will not extend over the side seam flap 30 when the bottom closure group 16 is in constructed form. This is covered in detail in the above mentioned U.S. Patent 3,120,335.

When the container is being assembled the equipment being used to form the tubular container member 80 may be operating much faster than Was formerly the case. Many times these operations are performed when the container is on the fly. In other Words, bottom forming may take place when the container is moving and not when it is in a static position. Also, in some applications the container paperboard is of small thickness and/or reduced density causing a limited flapping action because of reduced stiffness in the material.

If the container tuck-in ap 56 moves into a pocket 82, shown in FIGURE 6, formed by tuck-out flap 58 and fold-back panels 65 and 68, its straight edge 72 may have been caught by the straight edge 7S of the tuck-out flap 58. This could cause the edge of the tuck-in iiap 56 to roll back, providing a poor bottom and sometimes a completely defective container. In some applications the bottom closure group even with a defective bottom could be closed and this defect would not be visibly noticed but because of the additional layer caused by the fold-back of the tuck-in fiap 56, bottom leakage could develop causing not only a defective container but a defective container in shipment. This can cause not only a loss of the packaged product if the product is a liquid, but also damage by permitting the liquid to pass over other containers if packaged in an open container case, or if packaged in a corrugated case could ruin the Whole case as a means of carrying the contents. Therefore, the present invention, which includes the camming edges 71 and 73, has a much larger area of pocket 82 for straight edge 72 to hit and also decreases the length of straight edge 72 which establishes better rigidity of the tuck-in flap 56. If the straight edge 75 would hit the cam edges 71 and 73, the cam edges will continue to pass the tip of tuckin ap 56 into the pocket 82 forming a good bottom closure and prevent the spoilage and damage at the packaging machine or during transit as discussed above.

FIGURE 2 illustrates an alternate embodiment of the present invention and provides a bottom edge member 7 0' which is similar to bottom edge member 70 except for a diagonal edge 73 which replaces the cam edge 73 illustrated in FIGURE 1. The cam edge 71 would remain the same. This may be adequate in some applications because any critical contact with diagonal edge 76 Would be prevented by the cam edge 71. If there was contact on the cam edge 71 the critical fold-back would be prevented from occurring because of the stepping down of the bottom edge member 70 from straight edge 75 to the edge portion 77 by the diagonal edge 7 6.

The typical sizes of the embodiments illustrated in FIGURES 1 and 2 would be used ou containers presently made to handle quarts, pints, half-pints and third-pints, for examples. The cross-section of the side wall panels; for example, would be in the neighborhood of 2.764 inches running from the middle of score lines 21 and 22 as an illustration.

Referring to FIGURE 3 We see another embodiment of the present invention which is provided with a bottom closure group 16 similar to the bottom closure groups discussed above and illustrated in FIGURES l and 2. Bottom edge member 70 is similar to the bottom edge members 70 and 70 illustrated in FIGURES l and 2, respectively. The tuck-in ap 56 has a cam edge 85 which initiates from the side edge 18 and terminates at straight edge 86. The cam edge has a reverse curve 87 just prior to terminating where it intersects straight edge 86. The intersection of the reverse curve 87 of cam edge 85 and straight edge 86 is substantially at 90 and forms a guide tip 89; Cam edge 91 initiates from the edge portion 74 in a shape similar to cam edge 85 and has a reverse curve 92 prior to its intersecting termination with straight edge 86. The reverse curve 92 intersects straight edge 86 at substantially a angle and forms a guide tip 94. By providing for the reverse curves 87 and 92 the outer extremities of cam edges 85 and 91, in other Words, the portions adjacent the score line 21 and the side edge 18 shall define the size of side wall panel 26 and tuck-in panel 56 but the area of the tuck-in panel 56 can be reduced down a small portion from the straight edge 86 by the reverse curves 87 and 92 which form termination points generally referred to as the guide tips 89 and 94, respectively.

A preferred application of the embodiment illustrated in FIGURE 3 Would be used on larger size containers such as half-gallon and gallon cartons. Examples of the side Wall panel widths for a container as illustrated in FIGURE 3 would be 3.764 inches for half-gallon size containers and 5.531 inches for gallon size containers from the middle of score line 21 to the middle of score line 22. Such size containers are Well known and extensively used in the present commercial market.

The guide tips 89 and 94 can act on the inside surface of tuck-out iiap 58 and guide the tuck-in flap 56 into a pocket, similar to the pocket 82 illustrated in FIGURE 6, with the cam edges 85 and 91 acting on the straight edge 7S or diagonal edge 76 if such contact should be made. This again prevents any rolling back of the free end of the tuck-out flap defined by the bottom edge member 70".

In some applications it is desirable to have the cam edge of the tuck-in ap opposite the diagonal edge 76 contact the straight edge portion 72 or 86 of the tuck-in flap a greater distance from the score line where it starts which defines its side portion than the distance the diagonal edge 76 of the tuck-out flap contacts the straight edge portion 75 from the score line defining its side edge portion. However, this is not necessary in all applications.

Many modifications could be provided; for example, in some applications it could also be desirable to have only one cam edge portion on the bottom edge member 70 with a straight diagonal edge such as 73 illustrated in -FIGURE 2.

Some preferred embodiments of the invention have been illustrated and described herein. However, it is to be understood that minor modifications other than those discussed may be made in the bottom closure group structure of a container and still be within the spirit and scope of my invention, as herebefore defined and illustrated. Therefore, the embodiments shown in the drawings are to be considered as merely set forth for illustrative purposes, and are not intended to limit the scope of the invention.

Other modes of applying the principles of my invention may be employed, instead of those explained, change being made as regards the article and combinations herein disclosed, provided the features stated be any of the following claims or the equivalent of such stated features be employed.

I therefore particularly point out and distinctively claim as my invention:

1. A fold-in bottom closure for a tubular container comprising, in combination:

(a) a body group defined by four substantially rectangular side wall panels;

(b) a bottom closure group having first and second minor aps extending from two opposed side wall panels;

(c) said bottom closure group having a tuck-in flap and a tuck-out ap extending from the two remaining opposed side wall panels;

(d) a pair of fold-back panels connecting said first minor flap with said tuck-in and tuck-out flaps;

(e) a pair of fold-back panels connecting said second minor ap with said tuck-in and tuck-out flaps;

(f) a bottom free edge member extending substantially across the bottom of said bottom closure group;

(g) first and second straight edge portions forming said bottom free edge member along the bottom of the sections formed by said first and second minor aps and their pairs of fold-back panels, respectively;

(h) the distance from said first and second straight edge portions to the bottom of their said Side wall panels is substantially equal to one-half the width of said side wall panels;

(i) third and fourth straight edge portions of said tuckin and tuck-out aps forming part of said bottom free edge member along the bottom of said tuck-in and tuck-out flaps;

(j) the distance from said third and fourth straight edge portions to the bottom of their said side Wall panels is larger than one-half the width of side wall panels;

(k) guide means on said tuck-in flap to guide said tuckin ap between the inside surface of said tuck-out ap and the inside surfaces of its adjacent fold-back panels when said bottom closure group is closed;

(l) first and second cam edges as part of the bottom free edge member of said tuck-in ap and forming part of its guide means;

(m) first and second reverse curves as part of said first and second cam edges, respectively; and

(n) said first and second reverse curves forming first and second termination points with said third straight edge portion. v

2. A fold-in bottom closure as claimed in claim 1, having:

10 (a) said cam edge starts at the outside edge of said tuck-in ap and ends at a second termination point on said third straight edge portion; and

(b) the distance from said second termination point to said outside edge of said tuck-in Hap is greater than the distance from said first termination point to the side of said tuck-out iiap where said diagonal edge contacts said second straight edge portion.

3. A fold-in bottom closure for a tubular container comprising, in combination:

(a) a body group defined by four substantially rectangular side wall panels;

(b) a bottom closure group having first and second minor liaps extending from two opposed side wall panels;

(c) said bottom closure group having a tuck-in flap and a tuck-out flap extending from the two remaining opposed side wall panels;

(d) a pair of fold-back panels connecting said first minor flap with said tuck-in and tuck-out flaps;

(e) a pair of fold-back panels connecting said second minor flap `with said tuck-in and tuck-out flaps;

(f) a bottom free edge member extending substantially across the bottom of said 4bottom closure group;

(g) first and second straight edge portions forming said sbottom free edge member along the lbottom of the sections formed by said first and second minor flaps and their pairs of fold-back panels, respectively;

(h) the distance from said first and second straight edge portions to the bottom of their said side wall panels is substantially equal to one-half the width of said side wall panels;

(i) third and fourth straight edge portions of said tuck-in and tuck-out aps forming part of said bot'l tom free edge member along the bottom of said tuck-in and tuck-out flaps;

(j) the distance from said third and fourth straight edge portions to the bottom of their said side wall panels is larger than one-half the width of said side Wall panels;

(k) guide means on said tuck-in flap to guide said tuck-in ap between the inside surface of said tuckout flap and the inside surfaces of its adjacent foldback panels when said bottom closure group is closed;

(l) a side seam ap connected along the edge of said side wall panel and one of said fold-back panels of said second minor flap;

(m) the outside surface of said side seam flap is sealed to the inside surface of said tuck-in flap and its said side wall panel;

(n) a first diagonal edge forming part of said bottom free edge member along the lbottom of said tuck-out Hap;

(o) said first diagonal edge starts substantially at the outside edge of said tuck-out flap from the Said second straight edge portion and ends at a first termination point on said fourth straight edge portion;

(p) first and second cam edges as part of the bottom free edge member of said tuck-in flap;

(q) said first and second cam edges start at the outside edges of said tuck-in flap and ends at second and third termination points on said third straight edge portion;

(r) said first cam edge passes by said first diagonal edge when said bottom closure group is closed;

(s) the distance from said second and third termination points to said outside edges of said tuck-in flap of their said respective cam edges is greater than the distance from said first termination point to the side of said tuck-out flap where said first diagonal edge starts from one end of said outside edge of said tuck-out flap;

(t) rst and second reverse curves as part of said second and third termination points, respectively; and (u) said first and second reverse curves forming said second and third termination points at substantially a 90 angle with said third straight edge portion.

4. A fold-in bottom closure as claimed in claim 3,

having:

(a) a second diagonal edge forming part of said bottom free edge member along the bottom of said side seam fiap;

(b) said second diagonal edge starts at one end of said second straight edge portion and extends substantially across said side seam flap towards said body group; and

(c) said tuck-out flap extends short of said second diagonal edge when said bottom closure group is closed.

5. A fold-in bottom end closure for a container blank,

including, in combination:

(a) a body group;

(b) a top closure group connected to the top end of said body group;

(c) a bottom closure group connected to the bottom end of said body group;

(d) said container blank having two substantially straight side edges;

(e) first, second, third and fourth vertical score lines extending substantially the length of said container blank forming with said two side edges four sections having substantially equal widths and a side seam flap having a substantially narrower Width;

(f) first and second staggered score lines forming the connections between said top closure group and said bottom closure group with said body group, respectively;

(g) a top edge member and a bottom edge member extending between said side edges to form the top and bottom of said container blank, respectively;

(h) said first, second, third ad fourth vertical score lines with one of said side edges form first, second, third and fourth side wall panels as part of said body group;

(i) a tuck-in flap connected to said first side wall panel, a tuck-out flap connected to said third side wall panel, a first minor flap connected to said second side wall panel, and a second minor flap connected to said fourth side Wall panel;

(j) a first pair of fold-back panels connecting said first minor flap to said tuck-in and said tuck-out fiaps, and a second pair of said fold-back panels connecting said second minor flap to said tuck-out fiap and said side seam flap;

(k) a first, second, third and fourth straight edge portion forming part of said bottom edge member for said tuck-in flap, said first pair of fold-back panels, said tuck-out fiap and said second pair of fold-back panels, respectively, and said straight edge portions are substantially parallel to said second staggered score line;

(l) the distances from said first and third straight edge portions to said second staggered score line are substantially equal to each other and substantially equal to one-half the width of said side wall panels;

(m) the distances from said second and fourth straight edge portions to said second staggered score line are greater than one-half the width of said side wall lpanels;

(n) a diagonal edge portion connecting said third and fourth straight edge portions;

(o) a first cam edge connecting one of said side edges and said first straight edge portion;

(p) a second cam edge connecting said first vertical score line and said first straight edge portion; and (q) first and second reverse curves as the ends of said first and second cam edges acting at said first straight edge portion and forming first and second termination points.

6. A fold-in bottom end closure for a container blank as claimed in claim 5, including:

(a) the horizontal distances from said first termination point and the side edge of said first cam edge and said second termination point and the first score line is greater than the horizontal distance from the points where said diagonal edge connects said third and fourth straight edge portion.

7. A fold-in bottom end closure for a container blank as claimed in claim 6, including:

(a) said first and second reverse curves forms said first and second termination points with said first straight edge portion at substantially a angle.

References Cited UNITED STATES PATENTS 3,120,333 2/1964 Seiple 229-37 3,120,335 2/1964 Eggleston et al. 3,185,376 5/1965 Crawford et al. 229-37 XR 3,232,516 2/ 1966 Arslanian 229-37 3,270,940 9/ 1966 Eggleston et al. 3,291,369 12/1966 Crawford 229-37 3,365,115 1/1968 Pike 229-38 3,412,923 11/1968 Ihde et al. 3,421,678 1/ 1969 Thompson et al.

DAVIS T. MOORHEAD, Primary Examiner U.S. C1. X.R. 229-17 

